Air distribution duct assembly



Oct. 8, 1963 P. G. LA VIGNE 3,106,146

AIR DISTRIBUTION DUCT ASSEMBLY Filed June 20. 1961 2 Sheets-Sheet 1 s f n 34` I n INVENTOR.

v P. G. LA VIGNE AIR DISTRIBUTION DUCT ASSEMBLY 2 Sheets-Sheet 2 Oct. 8, 1963 Filed June 20. 1961 @i IN V EN TPR.

U d S P f O r awaits Ice Patented Oct. 8, 1963 semblyv embodying the invention and of :its elements will 305145 be better understood by reference to the following specifi- AIR DHSTRBUUN DUCT ASSEMBLY Paul G. La Vigne, La Habra, Calif., assigner to @wens- Corning Fiberglas Corporation, Toledo, Ohio, a corporation of Delaware Fiied .lune Z0, 1961, Ser. No. 118,331 3 Claims. (Cl. 9S-33) This invention relates to air distribution duct assemblies of .the type usually employed lwith dropped or false ceilings Iand which serve to deliver and distribute centrally heated or cooled air to enclosures such as oices, etc. within a building and, frequently, 'to carry return air back to a central heating or air-conditioning apparatus.

This application is a continuation of my earlier copending application, Serial No. 123,-6011 filed February 28, 1961.

rfhe invention consists in an air distribution duct assembly having elements which function for confining the air be-ing distnibuted, for delivering it to different portions of the enclosure, nor diffusing the air as it is vdelivered, and having ceiling-element-supporting means, and for cooperating, for example, with curtain walls for returning air.

The principal object of the instant invention is to provide a 4duct assembly having ta main spine-like structural element and a duct cooperating therewith, the spinelike element being generally channel-shaped, andfunctioning to support 'and retain the duct impl-ace, as Well as to deliver air `from the duct into-the space, such as a room or other enclosure, in question.

llt is another object tof the instant invention to provide an elongated air-distributing channel adapted to be supported from overhead structural elements at a ceiling level and adapted to support ceiling elements and to communicate with the interior of the enclosed, elongatedV distribution duct throughout the length of the channel, yfor diffused delivery of air into lthe area beneath the ceiling.

It is yet another `object of the instant invention to provide a yduct for an air distribution system comprising a sheet of heat insulation material or the like so designed as to enable it to be shipped as a dat sheet and be readily folded int-o 'an elongated duct adapted for rapid assembly with an air distribution channel at the dropped ceiling level of a roo-rn `or :other enclosure, the duct being held and supported by the channel inthe usual plenum that is formed above the dropped ceiling.

Ilt is yet another :object of the instant invention to provide an =air duct assembly comprising two main structural elements, viz., an elongated air distribution channel and an elongated enclosed air distribution duct, the two elements being assembled for mounting at the ceiling level, either `as an air supply duct assembly extending across a `generally central portion `of `a ceiling, or as an air return duct assembly mounted at the top of a curtain wall, there being return air passages leading through the Wall to its upper surface and into the duct lassembly mounted atop the curtain Wall.

lt is a more specific object of the ins-tant invention to provide 'a unitary air distribution channel suitable for fabrication as a metall extrusion and having Vsuitable portions with legs, webs and ilanges extending therefrom at suitable positions and `attitudes for `cooperation with ceiling elements, the side walls vof ducts, difusers, hanger means, ceilingT support assembly means, cap structures for curtain wall, etc., in order to readily assemble theseelements yaccor-ding to inodern, dropped-ceiling, curtain- Y wall, buil-ding constructions.

cation and to the attached drawings in which:

FIG. 1 is a fragmentary, vertical, and partly schematic sectional view through a room showing a dropped-ceiling and curtain-wall construction, and illustrating the ernployment of two duct yassemblies embodying the invention, one as an tairv distribution duct assembly, and ythe other as an air return duct assembly .in cooperation with a cuntainwall having ya return air passage.

FIG. 2 is a transverse vertical sectional view through a duct lassembly embodying the invention and shown on an enlarged scale. f

FIG. 3 is a fragmentary, perspective v-iew of a duct constituting a part of the instant invention, the same being shown in its original flat form as manufactured and before being folded to `forrnan elongated enclosed duct.

FIG. 4 is a cross-sectional View taken along the line 4 4 of FIG. 3 and shown on an enlarged scale.

FIG. 5 is a fragmentary view in perspective of the po-rtions of two duct sections such as shown in FlG. 3 and folded to form enclosed, elongated duct sections, the same beingshown assembled in longitudinal abutting relationship, one with the other, by Imeans tof a joint cover, and also showing portions of the air-distributing channel which constitute a part yof the assembly of the instant invention.

FIG. 6 is a perspective vie-W of a hanger for supporting a duct assembly embodying the invention from over- `head support means.

lnrnany modern buildings, such as those fabricated y'from structural steel and having reinforced concrete floors, the occupied spaces Within the building are bounded by dropped ceilings and so-called curtain Walls. This manner :of construction provides for a space, often two or three feet high kand'extending through the building just beneath each dio-oi', called a plenum, with individual rooms on the floor separated from each other -by curtain walls which extend from the floor upwardly to the dropped ceiling. The plenum thus provided over fthe `dropped ceiling and across the' tops of Vthe curtain walls is usually employed for the 'distribution of service elements and components, such as electrical cables, heating and air conditioning distribution systems, telephone cables, etc.

V`tFG.y 1 illustrates such a building construction, wherein there is shown van upper rfloor generally indicated at 1), and the next lower floor fragmentarily indicated at 1i. `Atta-ched'to the underside of the upper door itlA there is usually located a gridwork of overheady structural elements, for example, longitudinal support beams 12 and transversely extending support beams 13. A dropped 4ceiling in such a construction is often supported by a "nel i9, the Wall 17 frequently being fabricated from sound-insulating material and, as in the case of the instant invention, 'having -a plurality of return yair passages -2}.`Each of the freturnair passages'Ztircomrnunicates with its particular enclosed space through -a suitable .grill 2.

Air-distributing duct assemblies, 'according to the invention, are generally indicated in FIG. 1 by the reference numbers 22 and 22a, one of such assemblies"`(22) being 3 disposed Iat the center portion of the enclosure under consideration, `and the other of such assemblies, indicated specifically by the reference number 22a, being shown atop the curtain wall 17. The air distribution duct assembly 22 is illustrated in FIG. 1 as functioning as a supply duct and the yassembly 22a as a return duct.

Referring more particularly to FIG. 2, which shows a duct assembly 22, each of the duct assemblies 22 and 22a comprises an elongated air distributing U-shaped channel generally indicated yat 23 and inver-ted to have an open bottom 24. Said channel 23 has two downwardly extending spaced legs 25 which, in the embodiment illustrated in the drawings, have inwardly offset upper continuations 25a that yare connected by a transverse web 25b at the upper end of the channel. The yair distribution channel 23 also comprises a pair of oppositely and outwardly directed flanges 29. Reference is here made to Patent No. 2,937,589, issued May 24, 1960, in which is disclosed an air outlet member or bar that embodies the abovedescribed spaced legs, inwardly offset legs, transverse web, and outwardly directed flanges.

The channel 23 also comprises two laterally spaced pairs of parallel spaced webs 26y and 27 which extend upwardly from the channel legs 25, 25a to a level below the web 25b. In the embodiment of the invention shown in the drawings, the two pairs of webs 26 and 27 are outwardly as well yas upwardly inclined and Aare located one on each side of a space 28 defined by the legs 25, 25a.

The flanges Z9 function to support ceiling elements, such as the T-bars 15, or, more directly, a ceiling panel such `as the ceiling panel 60 shown in the drawings, or lighting fixtures 30a, or other elements. At the outer sides of the legs 25, 25a and near their lower ends, each of them is formed with a pair of opposed slots 31 and 32 for the retention of the fiat arm of a bent clip 33, the clip 33 having a return-bent end 34 which is hooked, for example, in an aperture 35 near the end of one of the T-bars 15 in order to retain the T-bar in perpendicular abutment against the flange 29 of the channel 23 to provide two perpendicular ledges formed by the flange 29 and the cross bar of the T-bar 15 4for holding perpendicular edges of `a ceiling panel 30 or a fixture 30a.

In the embodiment of the invention illustrated in the drawings and following the teachings of Patent No. 2,-

Y 937,589, the uppermost part 36 of the inverted channel 23 extends upwardly beyond the pairs of parallel webs 26 and 27 `and a plurality of apertures 37 are drilled or punched in the leg extensions a near their tops. The channel part 36 has a T-slot 38 for the reception of heads 39 of a series of downwardly extending damper-adjustment screws 40 which are threaded through an inverted U-shaped damper 41. The lower end of each of the screws 40 is slotted so that a workman `can insert a tool upwardly through the space 28 to rotate the screw 40` for -adjusting the position of the damper 41 across and to partially close the apertures 37 for adjusting the flow of air therethrough.

Theair distribution channel 23 supports and cooperates with a duct generally indicated by the reference number 42, which, in the embodiment shown, is triangular in shape, having ya fiat horizontal top 43 and two downwardly and inwardly converging side walls 44. The duct 42 is fabricated from a flat rectangular sheet 45 (FIGS. G and 4), of, for example, a compressed, fibrous insulating material such as glass fiber wool. The sheet 45 has parallel edges 46 `and 47 and one face of the sheet 45 (lower face, FIGS. 3 and 4) is cut with two parallel V-shaped kerfs 43 and 49.' The kerfs 48 and 49 are equidistantly spaced from the respective nearer edges of the sheet 45, i.e., the `apex of the kerf 48 is the same distance from .the edge 46 as is the apex of the kerf 49' from the edge 47. The kerfs 48 Vand 49 are cut at least substantially through the sheet 45 land their sides meet at an angle equal to the difference between 180 land the included angle between the top 43 and side 44 (FIG. 2)

4 of the duct 42 when the sheet 45 is folded to form the duct 42. The central portion of the sheet 45 between the kerfs 48 and 49 forms the top 43 of the duct 42, and the sides or outer portions of the sheet 45 form the side walls 44 of the duct 42.

The sheet 45 is backed up by an imperforate casing sheet 50 which serves two functions. First, the sheet 5tlg preferably formed from 1a light-gauge metal such as aluminum, provides structural integrity for the kerfed sheet 45 so `as to retain the two side portions 44 and the central portion 43 of the sheet 45 as an entity; and second, the sheet 5t) functions as a vapor barrier and encloses the duct 42 in its formed position (FIG. 2). The sheet 50 is adhesively secured to the upper face of the sheet 45, i.e., the outer face of the duct 42, by a suitable adhesive generally indicated lat 51, by which the casing sheet 5t) is laminated to the fibrous sheet 45 preferably before the kerfs 48 `and 49 yare cut. The casing sheet 50 has a pair of elongated, upwardly protruding loop hinges 52 formed by bending the metal of the casing sheet 55 prior to assembly with the fibrous sheet 45, which hinges 52 arel aligned with Vand extend Ioutwardly from the apexes of the kerfs 48 and 49. The side edges of the casing sheet Sti are 'turned up, forming elongated lips 53, and the casing sheet 50 is longitudinally staggered relative to the fibrous sheet 45 so that the casing sheet 50 extends beyond the fibrous sheet 45 at one end (indicated by the reference number 54) and the fibrous sheet 45 extends beyond the casing sheet 5t) at the opposite end (indicated by the reference number 55). When two sections of duct 42 are assembled in end-to-end relationship, the overlapping end 54 of one of the casing sheets 50 overlaps the exposed end 55 of the next adjacent fibrous sheet 45.

The duct 42 is formed by bending the sides 44 of the fibrous sheet 45 downwardly toward each other, bending the loop hinges 52 of the casing sheet 50, until edges 56 of the sides 44 yand edges 57 of the center portion 43 (duct top 43) Iare in mutual contact -upon the closing of the kerfs 48 and 49. The duct 42 then has an inverted isosceles-triangular cross section with its top 43 extending generally horizontally `and its sides 44 converging downwardly. The outer edges 46 and 47 of the fibrous sheet 45 are bevelled so `as tonaccurately abut the outer sides of the leg extension 25a (FIG. 2) and the upper surface of a horizontal web 58 of the pairs of parallel webs 26 and 27.

After the duct `42 is folded into the isosceles-triangle configuration, the lower ends of the sides 44 are inserted downwardly between the pairs of webs 26 and 27 with the end of one of the sides 44 nesting between one of the pairs of webs 26 and 27 and abutting the web 5S and the lower end ofthe other of the sides 44 similarly nesting between the other pair of webs 26 and 27. As the lower ends of thesides -44 are inserted into place between their respective pairs of webs 26 and 27, the lips 53 at the sides of the casing sheet 50' are snapped beneath the down-turned rims 59 on the inner sides of the upper ends `of the outer webs V26. This engagement of the lips 53 with the rims 59 functions to lretain the duct 42 connected to the channel 23l and lalso to seal the space between the inner sides of the webs 26 and the portions of the outer sides of the duct sides 44 which extend downwardly into the spaces between the webs 26 and 27. This sealing is considered limportant because the casing sheet `5ft not only has its first function of giving structural integrity to the duct 42 before folding, but also has its second function of `serving as va vapor barrier and a heat reflector to prevent the passage `of vapor into or `out of the duct 42 and to reduce the heat transfer between either -cold lair or hot air interiorly of the duct 42 and the surrounding area of the plenum above the dropped ceiling.

Longitudinally adjacent sections of ducts 42 are assembled in end-to-end relationship, as described above and as illustratedin FIG. 5, where an. exposed end 55 of a brous sheet 45 is shown and the engagement of the casing sheet Sil with the rim 59 of `one of the webs 26 -is also illustrated. The joint between longitudinally abutting duct sections is overlapped, as explained, land also is covered by a formed metal cover ou having a top 61, two loop hinges 62, and downwardly extending arms 63 which closely embrace the corresponding elements of the casing sheet 50, and at their ends are simil-arly turned over to provide hooks (not shown) for engaging beneath the rims S9 and 59a of adjacent webs 26 and 26a of the two longitudinally abutting channels 23.

A duct assembly 22 *according to the invention is suspended from the overhead structural elements 12 and 13 by 'means of supporthooks 64 (FIG. 1), each of which is adjust-ably connected at the center of a cross channel 65 of a triangular hanger 66 (FIG. 6). The triangular hanger 66 also has two downwardly converging legs 67, each of which terminates in an inwardly turned hook 68 that is engageable beneath a downwardly turned flange 69 formed on the outer side of the outer web 26 o each pair of webs 26 and 27. The hanger thus supports the air distribution channel Z3 which, in turn, supports its cooperating duct 42 and ceiling elements such `as the ceiling -panel 33 or the T-bar 15.

The open bot-tom 24 fof the space 2S dened by the legs 25, 25a of the channel 23' has yan air diluser 70 which, in the embodiment shown, is a perforated trough fabricated from resilient sheet material and having turnedy tion is employed as a return duct, for example, the duct assembly 22a' shown in FIG. 1, it is identical with that previously described, except that it does noty employ a diliuser 70 and is assembled with a partition cap 19.`

The partition cap 19 is a channel having downwardly extending arms 72 embracing the upper edges of the partition `or curtain wall 17, and a central portion '73` which protrudes `upwardly into the space 28 between the legsV 25 of the inverted U-shaped channel 23. A series of apertures 74 is formed in the central portion 73` of the cap 19 to provide for the tlow of air upwardly out of the return 'air passage 2d into the `space 28, through that space and through the apertures 39 in the upper part 1of the channel 23, and into the interior of duct 42a of the duct assembly 22a.

Air ows `from the source through main floor ducts (not shown) to the air distribution duct assembly 22 of the invention, through fthe apertures 37 and the interior space 28 of the channel 23, and outwardly through the diiiuser 70, into the interior or" the space under consideration. Air ilow arrows are shown in FIG. 1. Return air flows through the rgrill 21 and return air passages 20 in the curtain wall, through the apertures 74 in the cap 19 into the interior space 28 of channel 23a of the return Aair duct assembly 22a, and thence to main return ducts `for the floor and to the air-treating apparatus.

Having thus described the inventionwhat is claimed and desired to be secured by Letters Patent is:

1. An lair distribution duct assembly for use in-ank enclosed space having a main ceiling and comprising, in combination, (1) an elongated air distributing channel member, said channel member comprising a lower portion comprising `a pair of laterall-y spaced, downwardly extending legs, and `an outwardly directed, substantially horizontal sub-ceiling element support ange on the lower end of eac-h of said legs, -said legs defining therebetween -a downwardly open air ilow space, `and an upper portion comprising a web extending upwardly from the upper portion of each of `said legs and a generally horizontal lcross element connecting said legs and webs in spaced parallel relationship, (2) a hollow, elongated, triangular air supply duct, said duct consisting of an inner layer of fibrous heat insu- 6 lating material and Ian outer, thin, sheet metal jacket for said insulating material and having a generally horizontal top :and two downwardly converging sides and means at the corners of the top and the sides of said jacket for connecting said top and said sides, the lower ends of said sides of said duct extending downwardly between said upwardly extending webs =on said channel member, there being air flow passageways. through Isaid upper porti-on of said channel member for communication between the air flow space delined by said legs of said channel member and the interior of said duct, means on said channel member -for spacing the lower ends of said sides of said duct from each other and on opposite sides of said air flow passageways through said upper portion, (3) an elongated lair flow diffuser at the open bottom of said air iiow space between said legs of said channel member and (4) hanger means for supporting said duct assembly from said main ceiling.

2. An air flow system in combination with a room having a regular ceiling and a dropped ceiling forming a plenum chamber therebetween and a curtain wall extending from t-he room oor to said dropped ceiling comprising a pair of elongated hollow-duct assemblies, means for supporting :one of said duct assemblies yat the ceiling level of said dropped ceiling in the plenum above said dropped ceiling and communication along its length with the room space beneath said dropped ceiling, said wall having atleast one return air passage therethrough communica-ting with said room space and yopening through the upper end tof said wall, means yfor supporting the 'other `of said duct assemblies in said plenum and atop said curtain wall with its interior in communication with the air passage in said curtain wall, said duct assemblies each comprising an elongated air-distributing inverted U-shaped channel having a bottom-open lower portion that is wider than the upper portion of the channel, two laterally spaced pairs `of spaced parallel webs extending angularly upwardly `from intermediate portions of the legs lof saidchannel and terminating below the upper closed end of the channel, an outwardly extending ceiling-element-supporting flange at the lower end of each leg of said channel, a hollow, elongated polygonal duct having downwardly extending sides, the lower end yof one lof said sides extending below the closed upper end of the channel between the webs of one pair thereof and the lower end of the 4other of said sides extending below the closed upper end yof the channel between the webs of the other pair, a thin imperorate casing enclosing said duct and extending downwardly within and below the upper edges of the outer webs of each pair of webs, the Vlegs of said channel having air passages connecting the space defined between said legs to the interior of the duct, an air diffuser removably disposed below the open bottom of the channel of the iirst of said duct assemblies, and a perforated cap mounted on the top of said curtain wall and extending into thek open bot-tom of the channel of the second of said duct assemblies.

3. A duct for an air distribution `system, said duct being fabricated from a ilat, rectangular sheet of compressed iibrous insulating rnaterial'having parallel edges, one face of said sheet having two parallel V-kerfs cut therein, the kerts being equidistantly spaced from the respective nearer edge of said sheet, the central portion of said sheet between the kerfs `serving as a top for said duct and the outer portions outside the kerfs serving as sides for said duct, the kerfs extendingat least substantially through said sheet and the sides of the kerfs meeting yat an angle equal to the diiierencebetween and the included angle between the top and the side of said duct when the sides thereof are swung downwardly for closing the kerfs, anda thin vapor-proof casing sheet adhered' to the opposite face of said fibrous sheet,l said casing sheet having an elongated, upwardly protruding loop hinge aligned with and extending outwardly from the apex fof each of the kerfs in `said fibrous sheet, said duct being formed into a hollow elongated sha-pe by folding said sides downwardly toward each otheiwith the sides of said brous sheet converging, and the edges of said central por-tion Vand said side portions of said brous sheet originally defining the kerfs being in mutual contact.

References Cited in the le of this patent UNITED STATES PATENTS Stacey July 4, 1933 Bernhardt Dec. 22, 1942 Tatsch Dec. 9, 1958 Rachlin May 24, 1960 

1. AN AIR DISTRIBUTION DUCT ASSEMBLY FOR USE IN AN ENCLOSED SPACE HAVING A MAIN CEILING AND COMPRISING, IN COMBINATION, (1) AN ELONGATED AIR DISTRIBUTING CHANNEL MEMBER, SAID CHANNEL MEMBER COMPRISING A LOWER PORTION COMPRISING A PAIR OF LATERALLY SPACED, DOWNWARDLY EXTENDING LEGS, AND AN OUTWARDLY DIRECTED, SUBSTANTIALLY HORIZONTAL SUB-CEILING ELEMENT SUPPORT FLANGE ON THE LOWER END OF EACH OF SAID LEGS, SAID LEGS DEFINING THEREBETWEEN A DOWNWARDLY OPEN AIR FLOW SPACE, AND AN UPPER PORTION COMPRISING A WEB EXTENDING UPWARDLY FROM THE UPPER PORTION OF EACH OF SAID LEGS AND A GENERALLY HORIZONTAL CROSS ELEMENT CONNECTING SAID LEGS AND WEBS IN SPACED PARALLEL RELATIONSHIP, (2) A HOLLOW, ELONGATED, TRIANGULAR AIR SUPPLY DUCT, SAID DUCT CONSISTING OF AN INNER LAYER OF FIBROUS HEAT INSULATING MATERIAL AND AN OUTER, THIN, SHEET METAL JACKET FOR SAID INSULATING MATERIAL AND HAVING A GENERALLY HORIZONTAL TOP AND TWO DOWNWARDLY CONVERGING SIDES AND MEANS AT THE CORNERS OF THE TOP AND THE SIDES OF SAID JACKET FOR CONNECTING SAID TOP AND SAID SIDES, THE LOWER ENDS OF SAID SIDES OF SAID DUCT EXTENDING DOWNWARDLY BETWEEN SAID UPWARDLY EXTENDING WEBS ON SAID CHANNEL MEMBER, THERE BEING AIR FLOW PASSAGEWAYS THROUGH SAID UPPER PORTION OF SAID CHANNEL MEMBER FOR COMMUNICATION BETWEEN THE AIR FLOW SPACE DEFINED BY SAID LEGS OF SAID CHANNEL MEMBER AND THE INTERIOR OF SAID DUCT, MEANS ON SAID CHANNEL MEMBER FOR SPACING THE LOWER ENDS OF SAID SIDES OF SAID DUCT FROM EACH OTHER AND ON OPPOSITE SIDES OF SAID FLOW PASSAGEWAYS THROUGH SAID UPPER PORTION, (3) AN ELONGATED AIR FLOW DIFFUSER AT THE OPEN BOTTOM OF SAID AIR FLOW SPACE BETWEEN SAID LEGS OF SAID CHANNEL MEMBER AND (4) HANGER MEANS FOR SUPPORTING SAID DUCT ASSEMBLY FROM SAID MAIN CEILING. 